From: "Theo de Raadt" <deraadt@openbsd.org>
Subject: Re: mosh aborts with pledge failure after network interruption or SIGSTOP
To: James Cook <falsifian@falsifian.org>
Cc: ports@openbsd.org, Jeremie Courreges-Anglas <jca@wxcvbn.org>
Date: Thu, 10 Sep 2026 12:26:34 -0600

James Cook <falsifian@falsifian.org> wrote:

> "Theo de Raadt" <deraadt@openbsd.org> wrote:
> > 105 is setsockopt
> > 
> > Please ktrace -di, and kdump to identify the parameters to the final setsockopt
> > before it gets pledge SIGABRT.
> > 
> > The first argument to setsockopt is the socket fd, and it has 2 arguments
> > are level and optname.
> > 
> > Scan up the kdump manually to see how that fd is allocated.  My guess is that
> > this socket is created as AF_INET6, and the setsockopt parameters are IP_TOS.
> > But this could be another new setsockopt that also needs bypass treatment in
> > pledge.
> > 
> > Show the combination of proto, level, and optname.
> > 
> > Please don't send a massive kdump.  Try to do what I've explained.
> 
> Here are the last few lines of output from kdump:
> 
>  26783 mosh-client CALL  socket(AF_INET6,0x2<SOCK_DGRAM>,0)
>  26783 mosh-client RET   socket 5
>  26783 mosh-client CALL  setsockopt(5,0<ip>,3,0x7207d0cea92c,4)
>  26783 mosh-client PLDG  setsockopt, "inet", errno 1 Operation not permitted
>  26783 mosh-client PSIG  SIGABRT SIG_DFL
> 
> Looks like you were right; 3 is IP_TOS.

OK.  Try the newest snapshot please.